In recent years, electronic organs have generally been equipped with a memory function which enables the tone color and sound volume to be set and stored, and enables the thus set tone color and sound volume to be recalled by one-touch operation.
FIGS. 8A and 8B illustrate a conventional volume control apparatus used with electronic organs, including an operator frame 40 which is an apparatus body. The operator frame 40 has, for example, five through holes 44 in which will be inserted depress operation members 42a of a volume select switch 42 and five through holes for illumination portions of lenses 48 of light-emitting diodes 46 to indicate the volume. A printed board 52 having the light-emitting diode 46 and a switch body 42b of the switch 42 mounted thereon is arranged under the depress operation members 42a and lenses 48.
There has also been widely known a volume control apparatus which consists of a slide volume control that can be moved both by hand and motor, and in which a knob represents an indication position.
According to the conventional apparatus mentioned above, when five switches 42 are arranged, the sound volume can be changed in five steps only. Further, the switch 42 that must be depressed cannot offer the smooth operation feeling provided by a slide volume control. As for the indication of volume, only one light-emitting diode 46 corresponding to a given volume level is turned on to indicate the volume level, so that the volume level is not readily recognizable from the position of the switch 42 unless the indication therefor on the apparatus body is read. This is not advantageous from the standpoint of playing music.
According to the conventional apparatus in which the volume can be changed continuously by a slide volume control, the mechanism is so complex as to result in a higher manufacturing cost and be more liable to become defective.